A substrate alignment device includes a plurality of state detection units, each of which is configured to move from a standby position to a detection position for detecting a positional state of a substrate and return back from the detection position back to the standby position, and a multidimensional robot arm configured to receive and support the substrate, transfer the substrate to a substrate detection site, and adjust the substrate in at least one orientation or position according to the detected positional state of the substrate to position the substrate to a target position for overlay mark measurements.